A. Technical Field
The present invention relates to data communication networked control systems and, more particularly, to systems, devices, and methods of securing data transmission in industrial process control architectures.
B. Background of the Invention
Industrial network system integrators are tasked with ensuring that networked devices in the factory automation business properly communicate with each other so that they can perform complex functions without introducing unwanted downtime. However, industrial process control architectures oftentimes comprise PLCs from a particular vendor, wherein the PLCs have certain proprietary IO interfaces unique to that vendor, and sensors and actuators from another provider, who uses a different proprietary interface.
Programmable logic controller (PLC) manufacturers and system integrators are primarily concerned with maintaining safety, transparency, and functionality. Sensor manufacturers share these goals, but in addition are often concerned about preventing unauthorized copying of their products and maintaining their reputation.
One approach that system integrators take to ensure interoperability is to employ devices with universal, standardized, network-independent interfaces, such that devices can communicate with each other over standardized communication protocols.
One such standardized communication protocol, which is incorporated herein by reference and will not be described in detail, is IO-Link. IO-Link is a communication protocol that is increasingly employed in process control systems as a fieldbus-independent standard for industrial point-to-point serial processing between a master and a device, for example, to remotely monitor and control smart sensors and actuators. Constant bi-directional communication and access to device-specific information enables remote parameter control and monitoring of networked devices. Data are accessed and exchanged with a standard protocol, standardized cabling (typically with unshielded, three-conductor sensor cables that simplify wiring), and standardized connectors. Increased integration and utilization of sensor and actuator information allows the system to detect and alleviate incidents in a process faster and more effectively. Thus, a high level of productivity and transparency can be maintained in automation facilities and other networks. Backward compatibility with conventional 24 V DI/DO devices adds to the attractiveness of IO-Link to system integrators.
However, IO-Link, like other traditional systems, provides no mechanism for authentication. A sensor or actuator device is typically connected to a host via a powered cable; the host interrogates the device in order to determine how to communicate with and drive the device. Due to fairly simple, handshake-type communication present in existing networks that lack authentication mechanisms and other security features, nothing prevents a sensor or actuator from falsely signaling compatibility with any other device or exhibiting a different behavior during operation than is expected.
What is needed are tools for system designers to overcome the above-described limitations.